Ed Miliband, who proposed a new capitalism built around British values that reward hardworking grafters and producers in business, and not asset-stripping 'predators'. Photograph: Jonathan Hordle / Rex Features Jonathan Hordle / Rex Features/Jonathan Hordle / Rex Features

Ed Miliband has insisted that his call for a clampdown on predatory corporate practices is not anti-business, but an "anti-business as usual message".

Speaking the day after his keynote speech to the Labour conference, the party leader said he was laying out a "serious argument" for an end to the "anything goes" culture and insisted Labour remained "firmly in the middle ground of politics".

Signalling a new era for Labour, Miliband also stressed his belief that spending more was not going to be route to achieving social justice in the next decade.

He also brushed off claims that his appearance struck many as "weird", saying he did not care what people thought of the way he looked because he strongly believed that "substance wins out".

The Labour leader outlined his views on the future of the country, which he said would "resonate" with the British public.

His keynote speech proposed a new capitalism built around British values that reward hard workers and producers in business and not asset-stripping "predators", as he sought to draw a line under the "something for nothing" system from the Thatcherite era, which he said New Labour had failed to correct.

He pledged to rein in excessive pay at the top of business, break up cartels and demand responsibility from the banks.

But his message that a future Labour government would treat "good" and "bad" companies differently to encourage responsible behaviour brought a mixed reaction from the business sector.

Miliband told BBC Radio 4's Today programme that his message was "pro-business" and would chime with people up and down the country.

"This is not an anti-business message, this is an anti-business as usual message," he said. "That is the most important thing about my speech yesterday.

"For me, predatory behaviour is when a business does something which is in its own short-term interests but does significant damage to the long-term health of the economy.

"The government can't legislate for all of that or regulate all of that, but it can set the rule of the games so that it encourages good practices. Take the reforms that are being talked about in the banking industry – that is precisely designed to prevent the kind of behaviour that we saw in the financial crisis."

Miliband denied he was seeking to make "moral judgments about individuals" in his new approach to business and welfare, saying instead that it was a matter of shaping the tax and regulatory regime so it encouraged people to act responsibly.

In his speech, he offered a new bargain in which rich and poor alike can get ahead so long as they play by the rules of the "quiet majority". He called for councils to not simply to take into account need, but also people's contribution to society – "whether the recipients are working, whether they look after their property and are good neighbours".

He told Today the public did not want a system under which "anything goes", saying: "It's not about heavy-handed government.

"The state sets rules in relation to our benefit system, social housing and the way our economy works. It is not like there is an option of not having rules, it's about what kind of rules they are – are they rules based on a set of values?"

He "definitely" wanted to take Britain to a new era that moved away from the 1980s culture "that as long as people maximise their short-term interest, everything will be OK in business and elsewhere".

"It was wrong … it has caused problems for our society," he said.

"We have got to choose as a society – do we change it or do we carry on as we are? Do we say: 'We had this banking crisis but it was just a little local difficulty,' or do we take a long hard look and have a new reckoning and things do have to change?"

Asked whether he wanted to take the UK into a "post-Thatcher/Blair era", Miliband replied: "Definitely. Definitely. Tony Blair was elected leader 17 years ago. He was dealing with different challenges. It is a new era – it has got to be a new era."

He said the new circumstances in which Britain found itself meant Labour must in future rely on change of this kind, rather than increased spending, to achieve its social goals.

"For the Labour party, spending is not going to be the way we achieve social justice in the next decade," he said.

"Of course we want to get the deficit down, we want to invest in public services. But actually, unless we reform our economy, unless we find ways of tackling these issues – and this has been a problem for the Labour party for decades – unless we get that political economy right, we are not going to get the change we want to see.

"It is right for the country, it is right for my party and it speaks to our values."

In a round of interviews on Wednesday, Miliband insisted Labour was not lurching to the left.

He told ITV's Daybreak: "The idea that you shouldn't have responsibility at the top of society – it is not a leftwing thing to say that there should be responsibility. It is absolutely in the middle ground.

"It is absolutely about the values of the British people, which says that everybody should show responsibility."